One patch antenna with dual-band dual-mode (DMDB) characteristic based on mushroom structure is designed and analysed in this study. The antenna operates at two modes: the bidirectional mode with endfire radiation patterns and the directional mode with broadside radiation patterns. The equivalent circuit, dispersion diagrams, field distributions, reflection coefficients and radiation patterns are given for confirming the working principle. Compared with the former DMDB antennas, array antenna could be designed to realise gain enhancement for both the two modes. Both element and 1 × 2 array antenna prototypes were fabricated for verification. The measured results show that the two modes resonant at about 9.8 and 11.95 GHz, respectively. Comparing with the element, gain enhancement of about 2.8 and 2.1 dB are realised by the array for the endfire and broadside modes, respectively. With pattern diversity and array realisation, this antenna type owns potential application value in wireless communication systems.

中文翻译：

---

基于蘑菇结构的微跳线槽馈电双频双模元和阵列天线

本文设计并分析了一种基于蘑菇结构的具有双频双模（DMDB）特性的贴片天线。天线以两种模式工作：具有端射辐射图的双向模式和具有侧面辐射图的定向模式。给出了等效电路，色散图，场分布，反射系数和辐射图，以确认工作原理。与以前的DMDB天线相比，可以设计阵列天线来实现两种模式的增益增强。都制作了单元和1×2阵列天线原型进行验证。测量结果表明，这两种模式分别在大约9.8 GHz和11.95 GHz处谐振。与该元素相比，增益提高了约2.8和2。阵列分别对端射模式和宽边模式实现1 dB的增益。通过模式分集和阵列实现，这种天线类型在无线通信系统中具有潜在的应用价值。